the vanadic acid is complete, the liquid in the flask—which contains the
vanadium as vanadyl salt and the molybdenum as molybdic acid—is treated
with hydrogen sulphide in a pressure bottle ; the molybdenum sulphide
precipitated is collected in a Gooch crucible, transformed into the trioxide
as in the determination of molybdenum in molybdenum steels, and weighed.
5. Determination of the Chromium.—See above, p. 190.
The vanadium content of vanadium steels is usually about 0-2% and scarcely
ever exceeds i%.
Chromium and nickel are often associated with the vanadium, chrome-
vanadium, nickel-vanadium and chrome-nickel-vanadium steels possessing the
valuable properties of vanadium steels along with those of chrome and nickel
Small quantities of vanadium may be found in ordinary cast-irons when
vanadiferous ores have been used for their manufacture.
The compositions of certain vanadium, nickel-vanadium, and chrome-nickel-
vanadium steels are -as follows (Mars, Geiger) :
Composition of Vanadium Steels
For locomotive frameworks ..... For tools and instruments .....
O-22 O -6-1-0
For toothed gearing for automobiles
. — -
For automobile hubs
Molybdenum steels are highly ductile, elastic and resistant to brealdng,
and are therefore mostly used for tools, although the cheaper tungsten
steels are usually preferred for this purpose.
Their analysis includes, besides determinations of the elements usual
in ordinary steels (carbon, silicon, manganese, phosphorus, sulphur), also
that of molybdenum and, sometimes, of tungsten, chromium, nickel, etc.
1. Determination of the Molybdenum.—When the iron has been
separated from the molybdenum by fusion with sodium peroxide and lixivia-
tion of the product with water, the molybdenum is precipitated in thetion of the Carbon, Silicon, Manganese, Phosphorus